Along with the development of medical technologies, beneficial components present in body tissues such as stem cells or platelets are used for treating diseases or applied in surgical procedures.
The stem cells are classified into embryonic stem cells and adult stem cells as well known in the art, and the adult stem cells are known as being distributed in bone marrow, cord blood, or fat tissues.
Such a stem cell is defined as a cell having self renewal properties by which the cell is repeatedly divided, multipotency properties by which the cell is divided into various tissues, and pluripotency properties by which the cell is divided into all kinds of cells.
In addition, when a wound occurs, the platelet secretes growth factors through a series of cascade processes while trying to stop the bleeding. In more detail, the platelet is a Platelet Rich Plasma (PRP) included in the whole blood, which may be obtained by centrifugally separating the whole blood. The PRP includes Platelet-Derived Growth Factor (PDGF), Transforming Growth Factor (TGF), Epidermal Growth Factor (EGF), and so on. These growth factors are known as factors involved in controlling neovascular promotion essential to regeneration of tissues, chemotactic and maturation promotion of cells, stimulus and increase of stem cells, organic synthesis, and so on.
For this reason, the tendency to clinically utilize the stem cells and the Platelet Rich Plasma (PRP) is increasing.
Presently, various methods are being performed to extract a target cell from the stem cells or to efficiently obtain a platelet or a PRP from the whole blood.
When clinically extracting a target cell (an adult stem cell), the target cell is extracted from fat tissues and bone marrow, and the process of extracting the stem cell from the bone marrow is substantially similar to the process of extracting Platelet Rich Plasma (PRP) from the whole blood. For this reason, the process of extracting PRP from the whole blood will be described below.
First, an injector for collecting blood and a centrifugal separation tube for centrifugal separation are prepared. At this time, the injector uses a cylinder equipped with an injection needle and a common injector made to function like a piston, and the centrifugal separation tube is a common container which receives a predetermined substance therein and has an upper portion sealed by a cap.
The blood collecting injector is used for collecting the whole blood. Here, the injector employs a 10 cc blood-collecting injector. For example, 8.5 cc of blood is collected by using a 10 cc injector containing 1.5 cc of Acid Citrat Dextrose (ACD) solutions which is an anticoagulant, then put into a 10 cc centrifugal separation tube, and then centrifugally separated in a centrifugal separator.
If the blood is centrifugally separated, as shown in FIG. 1, the blood is divided into three layers of a Red Blood Cell (RBC) layer, a Platelet Rich Plasma (PRP) layer containing a lot of platelets, a Platelet Poor Plasma (PPP) layer from the bottom of a centrifugal separation tube 2 due to the specific weights. At this time, the Platelet Rich Plasma (PRP) is also called a buffy coat. In other words, the blood is divided into a blood cell component including the RBC layer and a blood cell plasma component including the Platelet Rich Plasma (PRP) and the PPP. At this time, Platelet Rich Plasma (PRP) is collected from the middle layer (PRP layer) other than the RBC layer and the PPP layer, by using a new 5 cc injector to which a long spinel needle is mounted.
Meanwhile, for the enrichment of platelets, the centrifugal separation process and the process of collecting the enriched Platelet Rich Plasma (PRP) are repeated again.
In this process, it is needed to give attention to not collecting the Red Blood Cell (RBC) together when the Platelet Rich Plasma (PRP) is collected. In other words, it is important to collect only the Platelet Rich Plasma (PRP) (blood plasma component). For this reason, in order to separate the Platelet Rich Plasma (PRP) layer and the RBC layer, a method for centrifugal separation by putting a cell isolation gel is used.
The cell isolation gel is an isolation solution with a concentration between the specific weight of the red blood cell and the specific weight of the platelet, and Ficoll™, Percoll™ or sucrose derivatives are used. In other words, as shown in FIG. 2, if blood is put into a centrifugal separation tube 2 including a cell isolation gel Vf and is treated by a centrifugal separator (not shown), the blood in the tube 2 is divided into an upper blood plasma component and a lower blood cell component with the cell isolation gel Vf as a border layer.
Therefore, as the RBC and the Platelet Rich Plasma (PRP) are separated by the cell isolation gel Vf, it is possible to safely collect only the Platelet Rich Plasma (PRP) by using a new 5 cc injector 1 to which a long spinel needle is mounted, so that the RCB is not extracted together from the Platelet Rich Plasma (PRP) layer (see FIG. 3).
As described above, various kinds of centrifugal separation tubes and injectors for extracting Platelet Rich Plasma (PRP) from the whole blood have been suggested. For example, Korean Patent Registration No. 10-0430893 discloses a serum dividing injector configured to collect blood by using an injector and then use the injector as a centrifugal separation tube, and Korean Utility Model Registration No. 20-0269465 discloses a centrifugal separation tube and a blood collecting injector containing a serum dividing gel, which forms a gel container in a blood collecting tube, collects blood therein, followed by cutting a container rod, and is sealed by a sealing cap and performs centrifugal separation.
However, the above methods consume too much time and collect the platelet layer (cell plasma components) inconsistently, and have the risk of red blood cell layers collecting together. Therefore, it is not easy to give accuracy to clinic applications. In addition, the consumption ratio of injectors and centrifugal separation tubes used for collecting the whole blood and extracting blood plasma components increases.
To solve this problem, an automatic classification technique, a Platelet Rich Plasma (PRP) separation kit, and a cell isolation gel have been developed.
However, the automated equipment for automatic classification may not be easily used at general private hospitals, when considering its price and efficiency.
In addition, though various kits of various prices and performances are provided suitably for individual private hospitals, there is a burden in using these kits due to their high prices and the increase of consumables.
Moreover, since Platelet Rich Plasma (PRP) necessary at a surgical procedure needs to be extracted and then instantly used, the waiting time increases when the Platelet Rich Plasma (PRP) is extracted, which deteriorates the working efficiency.